Electronic release mechanisms for safety bindings have been developed as an alternative to traditional mechanical bindings. Although they offer advantages over traditional, mechanical safety bindings, electronic releases also suffer certain disadvantages. For example, they must be powered by a portable power source, such as a battery, which may fail and incapacitate the release mechanism.
In response to this problem, safety bindings that contain electronic release mechanisms have been combined with mechanical release mechanisms which are activated when the electronic release mechanism falls. One such binding is German Patent DE 3017841, which acts as a purely mechanical, hydraulic, or pneumatic emergency release mechanism when the electronic release does not function. When the electronic release mechanism does function, the mechanical, hydraulic, or pneumatic release is inoperative.
This release, however, still suffers important shortcomings. First, the acceptability of this binding to skiers is limited because, like bindings whose releases are totally electronic, the shocks received by the ski are directly transmitted to the skier's leg. Thus, the electronic release is constantly being exposed to shocks and is likely to fail. Second, when pressure on the system occurs due to relatively weak forces of low value over a long period of time (for example, the forces which occur as a result of changing weight of the skis by 180.degree. direction changing of the skis) the risk of undesired releases increase. Third, in the event that the electronic release mechanism fails, the mechanical, hydraulic, or pneumatic release system which becomes operative may be adjusted differently from the electronic release, thereby causing the skier great difficulty. This occurs because the mechanical, hydraulic, or pneumatic release is adjusted independently from the electronic release system. Thus, when the electronic release system fails, the skier may suddenly find his boot held to the ski by a binding that has a release threshold and characteristics considerably different from the characteristics and threshold which were in operation before the failure of the electronic system. This situation is extremely detrimental to the safety of the skier, who suddenly finds himself in ski conditions which do not correspond to his level of expertise.
Thus, there is a need for a safety binding having an electronic release which coacts with a mechanical, hydraulic, or pneumatic release mechanism to ensure optimal retention even in the event that the electronic release fails.